In order to determine that a call placed from a non-regulated or COCOT paystation telephone has been answered by the called station, it is customary for the answer supervision or call progress circuit which carries out this task to monitor the line for presence of voice signals that originate at the called station when a party at the called station picks up the line. Because voice signals may also be placed on the line from the calling paystation, which could deceive the answer supervision circuit, the paystation transmitter's microphone is normally muted until it has been confirmed that the called party has answered the call. Unfortunately, this muting of the paystation microphone makes it impossible for the called party to receive voice signals from the calling paystation. Namely, when the called party answers the call (for example, by saying `Hello`), any voice reply by the calling party will not be placed on the line until the answer supervision circuit has determined that voice from the called station is present on the line and has removed the muting of the calling party's microphone. Depending upon the performance of voice detection circuitry employed by the call progress circuit, the delay involved before the mute is removed may be significant enough to frustrate the called party into thinking that the line is dead, whereby the called party hangs up. Thus, although muting of the COCOT's microphone is intended to prevent the calling party's voice from interfering with answer verification, it introduces a problem of its own, to wit--the answering party hanging up when no reply from the muted calling party is heard.